You hit you glass 3 times and only then decided to have a go at pressing the button! How much damage have you done to the window 🙁
On the tennis ball myth. The old golfs used to work on a pnumatic system. I think the pump was in the boot so thats why they reckoned a tennis ball would 'pop' the locks in this case. Not a chance these days.
If it makes any of you guys feel any better, in all the years i have worked in the motor trade i have yet to find a mechanic who had any idea how to break into various vans (VW, Ford, Iveco, Merc) and have always had to resort to breaking windows (Cheaper for dealers). I once had to grind off a set of rear door hinges on a ford transit with fridge conversion and remove both doors in once piece still locked 🙁
Personally in that situation i would have called the AA/RAC.